Apparatus and process for controlling humidity of gases in drying operations.



H. D. TIEMMN. APPARATUS AND PROCESS FOR GONTROLLING HUMIDITY OP GASES IN DRYING OPERATIONS. APPLICATION FILED MAR. 29, 1910. 963,832, Patented July 12, 1910.

l prising various STAES HARRY D. TIEMAN'N, OF WASHINGTON, DISTRICT OF COLUMBIA.

APPARATUS AND PROGSS FOR CONTROLLING HUMIDITY OF GASES IN DBYING- OPERATIONS.

Specification of Letters Patent.

Applicationled March 29, 1910. Serial No. 552,284.

ratenteaauly 12, 1ero.

(DEDICATED To THE PUBLIC.)

To all whom 'ltmay concern:

- Gases in Drying Operations and have madeapplication hypetition of even date herewith, under the act lof March 3, 1883, chapter 143, (22 Stat., 625,) praying that Letters Patent therefor maybe granted to me.

The invention herein described and claimed, may be used by the'Government of the United States or by any of its officers and employees in the transaction of work for the Government, or by any person in the United States, without payment of any royalty thereon.

The following isthe specification of `my invention:

The object of my invention is to impart to air or other gas, used for drying or humidifying operations, a constant absolute humidity of any desired amount, and a means for regulating or controlling the same. To accomplish this result an excess of humidity is at first given to the current of gas, providing its humidity is deficient, by-injectin'g steamv under pressure, subject to -regulation directly into the gas and sub.

sequently condensing the excess of humidity sure to the exact amount required, by contact with a cooling spray of water the temperature'of which may be regulated according to the vapor pressure, that is the absolute humidity, desired. Subsequently any suspended particles of moisture received from the spray are separated from the gas, and it may then be heated to whatever final temperature was desired.

I am aware that numerous apparatus comcombinations of steam sprays, water sprays, eliminators, and heaters have been invented and Letters Patent granted therefor. M method and apparatus is believed to l iden essentially from any of them, in that I obtain the exact vapor pressure desired by a reduction of the temperature and pressure of vapor from a previously higher pressure and temperature to the exact amount required, by contact with water at a temperature less than that of the gas immediately before contact therewith, and at the same time I control the resulting vapor pressure or absolute humidity by regulatmg the temperature of the cooling water. The accompanying illustration shows an arran ement of apparatus designed to accomplis ed this iesult in the manner specified, but I do not restrict myself to the specific form of apparatus there shown, reserving the right to modify the same in any way consistent with the spirit 0f this, inven' tion, so long as it accomplish the desired results in a manner conforming to my claims.

In the illustration Figure 1 represents a sectional elevation'of the apparatus in the form of a horizontal rectangular ue or passage A A1 of suitable dimensions for supplying the requisite amount of air or gas, which is caused to ass therethrough in the direction indicated y arrows at a very slow velocity, so as to give ample time for the action of the condensing water and for separation of suspended particles of water by gravitation in the chamber A1. Y

B B represents a series of steam jets, supplied with pressure steam from the pi e V, the flow being' regulated by any suitable thermostat K. The device here shown consists of two solenoid coils g g1, acting in reverse order on an iron core or armature attached by a rod to the steam valvep, a dash-pot h, and a clutch which holds the rod stationary, cexcept when a current vis set up in either coil of the thermostat K.

of the thermostat J and coils G G1, de-

scribed further on. These jets are intended to impart to the entering gas, if deficient, a vapor pressure slightly in` excess of the final amount required, and consequently will' also raise the temperature of the gas if its ini'- tial temperature be less than ythat corre# sponding to the necessary vapor tension.

C C' is a fountain of water projected upward by the nozzle R and the spreader Z,

which returns in the form of rain into the trough T. The nozzle R may be an suitable form of hose nozzle, the preferre form being the Well-lmown one shown in Fig. 2, in which w is a perforated washer, having two4 or more holes near its-circumference, which normally register with similar holes inthe flange f of the cone c. The cone c is rotatable, so that by turning it the registration of the holes is more or less interfered with. With the holes normal a smoothl stream of water is delivered by the nozzle, but by turning the cone slightly it is broken up into spray.

1 is a detachable lip for reducing the size of the delivery orice.

The stream of water is delivered horizontally against a curved baffle plate Z,more or less semicircul'ar in shape and centrally located between -the'side walls. This plate is so shaped that it deflects the stream upward and outward in a fanlike manner, but so that the majority of the drops strike upon the upper horizontal wall or ceilingof the passage. vAt this point is placed a brush of' metal points, Q, which mightbe composed of a great number of ordinary brass pins driven through a brass plate, arranged in brush fashion. The stream coming in contact with this brush is brokenup into va great number of small drops, which fall from the points of the pins in the form of gentle rain, into the trough T. As the motion of the gas is very Islow, ample time is given for complete condensation of the excess vapor by contact with this spray. y

A1 is a chamber or portion of the flue A A1 of relatively large area.

D is a centrifugal separator consisting of a-circular flue considerably smaller in crosssectlonal area than that of the flue A A1, in whlch are arranged helical o1; auger-like b lades which impart to the air a rapld rotation as it ascends through the tube. This is intended to completely separate any remaining particles of moisture through centrifugal force. The water bein muchA heavier than the air is thereby t rown outward against the walls, where it trickles down by gravltation into the trough T below. If a orced clrculatlon of gas be used, a centrifugal fan may be placed at D, instead of the Statlonary blades, or the two may be combined. In some cases this centrifugal separator will be unnecessary and may be totally dispensed with. i

E is a heater of any desired kind,.havin a regulatable by-pass F as commonlyuse that amper e being controlled by a thermos a 1 d is a door by which entrance may be hadl to the interior of the apparatus.

- P is a mixing valve for supplying the nozzle R with water at the desired temperaj 654 ture, the waterv being supplied to P from a happen to be.

valve may be automatically'operated by any suitable thermostat J placed in the spray C C. In the instance here illustrated. the valve P is operated by a lever attached to order upon an iron core or armature. The motion 1s dampened by an adjustable dashpot H', so as to produce a very gradual movement of the valve. When there is no electric current in either coil the armature remains stationary for any position of the valve, but as soon as the thermostat J sets up a current in 'either coil,'the leveris moved slowly in that direction, thus changing the valve P, until the proper temperature is restored to the water-spray, and the current being again cut oi by action of the thermostat,l the lever remains stationary in its new position. To prevent any motion of the valve when thecurrent is cut olf, there is a clutch t on the rod which holds .a rod which 1s moved in either direction by two solenoid coils G Gr1 acting y1n reverse` it fast, except when a current is passed v the action is positive and static.

Having described the apparatus, I will now explain its operation upon :the gas.l

The air or gas first enters the .flue `A at whatever temperature or .humidity it may It is rst saturated by the live steam` at B B, and raised to a temperature slightly above that corresponding to the required vapor tension. O r if `its vapor tension be already suiiicient, no treatment is necessary by the s teamjets.` It next comesinto intimate contact with the cooler Water-spray, which cools the vapor and thus reduces it by'condensation to the required pressure or absolute humidity, dependent upon the temperature of the water. It then passes slowly through the large chamber A1 where allthe larger drops of water-held in ,suspension from the spray are precipitated found superfluous, and -it may then be env tirely dispensed with. The gas then passes on up through the heater E, and thence to 'the chamber where used. If saturated gas is required, the heater E is thrown out of action, and the gas is dellvered at the same temperature with which 1t leaves the waterspray. The parts are lso proportioned that lthe gas has a relatively rapid velocity in the water.

ditions are fulfilled. It

much above the temperature of the condens- A concrete example will illustrate the working'of the apparatus. Let us suppose that air is wanted for drying purposes at 100 degrees Fahrenheit, with 30 per' centof relative humidity. The dewA point will then be at .63 degrees and a vapor pressure corresponding to 63A degrees is called for. Suppose the available supply of air to be at 40 degrees. The thermostat at K is adjusted so that sufcient steam is imparted by the steam jet to raise the air and saturate it to about 68 degrees, or slightly above the temperaturev corresponding to the vapor pressure required. The temperatureof` the condensing water is then regulated vso as to reduce the temperature of the air to 63 degrees, as it passes throuvh into the .ch-amber A1. When the suspended drops of moisture iareiremoved, and the saturated air then heated to 100 degrees, the required conmatters not how ing water the incoming air be heated, provided only that it contain a vaporpressure in excess'of that required, so that it maybe reduced to the exact amount by contact with the water. For economical working, however, it is lbest to have the incoming` air saturated at a temperature only slightly in p excess of that of the water.

I claim :--l 1. A method of imparting. to air or other gas, for use in drying or humidifying operations, any desired vapor pressure, `and the means of regulating the same, consisting in first spraying steam into thegas suiicient to raise the vapor pressure to an amount in excess of that required, and subsequently reducing -it to the proper amount by intimate contact with a sheet or spray of cooling waterlwhose tem erature is less than that of the gas imme iately before contact therewith, and regulating thetemperature of the water in order to control the result ing vapor pressure, and separating the suspended particles 4of water received from the spray by gravitation `and centrifugal force `in the manner land sequence substantially as described. j

2. A method of imparting to air or other gas for use in drying or humdiying operations, any desired vapor pressure, and means ofregulating the same, consisting in bringing gas which already contains an excess of vapor into intimate contact with a stream or spray of cooling water whose temperature is less than that of the incoming gas, and regulating the temperature of imparted to the its absolute humidity to an amount in excessof thatrequired, and subsequently reducing the absolute humidity to the proper amount by intimate contact of the gas with a sheet or spray'of cooling water whose temperature is less than that of the gas immediately before contact therewith, and automatically regulating the temperature of the water in order to control the resultin absolute humidity, separating suspende particles of water from-the issuing gas, heating the gasv to the linal temperature, and automatically regulating the amount of steam initially as, in the sequence and manner substantia ly as described.

4. A method of su lying air or other gas l for drying or humitii ying purposes at any desired humidity and means for regulating the same, consisting in first spraying steam into the current of gas suhcient to raise its vapor pressure to an amount in excess of that required, and subsequently reducing the liu-- midity to the absolute amount required by intimate contact of the gas with a sheet or spray 'of cooling water whose temperature is less than that of the gas immediately before contact therewith, and automatically regulating the temperature of the water so as to control the resulting absolute humidity, separating the suspended particles of water from the issuing gas, producing a circulation of the gas, heating the gas to the linal temperature desired, and automatically regulating the amount of 'steam initially supplied to the'gas and also the nal temperature of the gas, all in thesequence and osesfany desired vapor pressure. and means q or regulating the same, consisting in the combination of a suitable flue or chamber A A1 of relatively large area, through which the gas passes, means for injecting steam under regulationv into the `entering gas to raise its vapor pressure to a point in excess of that required, means for producing aspray of water at a temperature less than that ofthe gas immediately before contact therewith, through which the gas passes, for

reducing the vapor pressure tothe required amount by condensation, means for automatically regulating the temperature of the water spray for the purpose of controlling vthe resulting vapor pressure of the gas, in a poses, any desired humidity and controlling the same, consisting of the combination of a suitable flue or chamber A A1 of relatively large area, through which the gasv passes,

means for injectingV steam under 4regulation 1nto the entering gas to ralse its vapor pressure to 'a point in excess of that required,

means of roducing a spray of Water at av temperature less than that of the gas immediately before contact therewith, through which. the gas is made to pass, for reducing the vapor pressure to the required amount by condensation, means for automatically.

regulating the temperature of the Water spray for the purpose of controlling the resulting vapor pressure, a centrifugal separator D, of smaller cross section than the flue A A1, for the purpose herein explained, and a heater E for raising the gas and vapor to the yiinal temperature desired in the sequence and manner substantially as described.l

7. An apparatus for imparting to air or other gas for drying or humidifying purposes any desired humidity and controlling sure to a point in excess of that -requ1red,

means for producing a spray of Water at a i temperature less thanithat of the lgas immediately before conta-ct therewith, through which the gas passes, forreducing the vapor pressure to the required amount by condensation, means for automatically regulatl into the entering gas to raise its vapor resing the temperature-of the Waterspray for the lpurpose of controlling the resulting Vapor pressure, a centrifugal fanl of' smaller crosssectional area than the space A1 for the purpose of forcing the current of air 'and at -the same time further separating suspended particles of Water lreceived from the spray by centrifugal force., and a heater for raising the as and Vapor to the final temperature desired, in the se uence and manner substantially as describe I Dated a't Washington, D. C., March 23,

HARRY D. TIEMANN. Witnesses:

THOMAS G. SHEARMAN, R. W. WILLIAMS, Jr; 

